Manual control device with power booster



April 21, 1953 R. H. ZEILMAN 2,635,532

MANUAL CONTROL DEVICE WITH POWER BOOSTER Filed Jan. 17, 1950 INVENTOR. ROY H.ZE/LNAN ATTOEN' E Y6 Patented Apr. 21, 1953 UNITED STATES PATENT assassa MANUAL CGN'IROL; DEVICE WITH POWER 7 BOOSTER. RoyfH. Zeilman, Elyria, Ohio, assigimr" re The Thew Shovel Company, Loraiii, Ohio, a

rationof Ohio Application January 17, wad-sensible; 139,031 4' Claims. (01. 121-41) 'There are many types of equipment such as,

for example, hoisting machines, power shovels, cranes and the like wherein the operating lever moved manually by the operator is functional to'control a clutch, brake orsome other device which requires the application of different degrees of force fordifierent stages of operation of the machine. Thus either the brake or clutchlever on a hoisting machine ismany times required' to be applied for an inching movement of the equipment whereas at other timesit isrequired' that the lever be applied with fullforce to either set the brake or clutch-.-

As the equipment increases in size or as the parts are more heavily loaded, the force required.

to-operate levers described to'their fullest extent. is so great that the work of operating them.

becomes exceedingly tiresome. For the operation of certain types of machinery it has never' been feasible thus farto entirely supplant manual; operation by means of mechanical or eras-- trieal operation. I There'are-many types of equip ment. wherein the actuation of the clutch or" brake, for example, can best be accomplished by.

the manual feel of an experienced worker.- This type of manual controlcan usually not be supplied by any mechanical or electrical means excepting with devices which are extremely com plicated and thus expensive'to" construct and and; at the same time, however, so assists theo'pe'rator' that he is relieved from the: burden-of; the heavy loads required to be placed. on the;

operating handle.-

It isa further object otfm'y invention to provide. an. apparatus of the characterdescribed which is extremely simple in itsv construction and.

To the accomplishment of the foregoing and related ends, said invention then. comprises the. features hereinafter fully describedancl particularly pointed out. in. the claims,- the following description and. the; annexed drawing setting. forth. in. detail certain illustrative embodiments of the invention these being v indicative; however, of butv a few of the various ways in which. the principle of the invention may be employed.

Inv said annexed drawing: v

Intheinset of the drawing. Ffig,- lis aside elevational view of one formof the operating lever having in association therewith a device: which is an. embodiment of. one form ofmy invention.

Fig. 2- is a: fragmentaryviewof; a portion of. a handle: similar to that. illustrated in Fig -h l, but shows a modified form of construction,

Fig, 3? is aside elevational view ofthe structure illustrated in Fig. 2., Q h

Fig; 4 is an enlarged sectional view-of one of the valve units which is shown associated with Referring .now more specifically to the. draw ingand more. especially to- Fig. 1, the construetioii here illustratedas one embodiment. of invention is shownto include a handle. generally indicated at 1- which ismounted on; a platform. 8 of amachine by; means. of. a tr-ur -1-nion 35 about which theha-ndle] may be pivotecl The upper.

end of. the. handle 1- carries a hand grip portion 9 by which. the handle 1- is usually manually controlled." Thehand. grip portion. 9 is pivotally secured: to the upper. end of the. handle. 7. by means: of the trunnion pin. 9a. Mounted. unopposite sides of the. handle i adjacent its. upper end. are; laterally extending. projections. [1 and [3,. each of which supports a valve unit,- the. con-- struction of which is most clearly illustrated in. Fig. 4 and; the; details; of; construction'. and m de of. operation ofwhichwill presently be descrihed. It-isasuflicient: at this-time. to poi-ntout. that. the

. valve members 'aa illustrated. inliig; s are each.

3 provided with an upwardly projecting actuating knob l4. On the left hand valve shown mounted on the upper end of the handle I the knob is indicated by the reference character IS. The manually gripped portion 9 of the handle is provided with lateral projections l and II. which are adapted to respectively engage the knobs l4 and [5 as the portion 9 is rocked in opposite directions about the axis of the pin So on which it is pivotally supported.

The bottom of each of the valves is provided with a pipe connection opening generally indicated at 4'! and into the valve mounted on the right hand side of the handle in Fig. 1 a fluid supply line l8 is threaded and into the opening 41 and to the valve mounted on the left hand side of the handle 1 there is secured the fluid supply line l9.

The fluid supply lines l8 and I9 are connected by suitable coupling means to a flexible conduit which leads away from the handle I to a fluid supply line 20a carried by the base of themachine. -Thefluid supply line 20a is connected to a suitable source of fluid under pressure.- Since the provision of fluid-under pressure is conventional, it is believed unnecessary to showsuch fluid'pressure supply means. I l

At this time itshould be pointed out that the apparatus illustrated in the description as illusrative' of my invention is designed to operate on compressed air so'that the fluid supply line 26a. in the illustrated embodiment of the invention is-connected to a compressed air tank.-

-=Extendingfrom the body of each of the valves is a passage which is shown provided with a conventional coupling 49. To the coupling 49 on the left hand valve on the lever is secured a conduit 22, which at its lower end is connected to a-fluid pressure motor 2|. To the coupling 49 on the valve on the right hand side of the lever is connected a flexible conduit 23 which at its lower end is connected to the fluid pressure motor 24.- I

The fluid pressure motors 2 and'24 are identical'in construction, said motor 2| comprising a piston 28 which'is reciprocable in a cylinder 60,

which at one-end carries a packing gland ring 65 and packing'ring 66 closely embracing the periphery of piston 28. The -other endv of the cylinder-60'--is threadably secured in a block 6| which'isprovided'with a passage-62 adapted to receive a conduit such as 22 (conduit 23 in the case of themotor 24) and provide communication to the interior of the cylinder 50. An ear on the end of the block 5| is provided-with an opening 61 adapted to receive'apin 61a and by which said-motor '21- maybe pivotally secured to-v a block such as 25 (21 in the case of motor 24) carried by the base of the machine. The extended end- 3| of the piston 28- is provided-with a transverse opening 63 which is adapted to receive a pin 32 by which one or both motors 2i and 24 may be secured to the lower end of the lever Motor 24 is, as indicated, identical with motor 2| excepting that its piston 29 extends toward the piston 28 of the motor 2 |--so that both pistons may be secured to the lever I by pin 32.

At its lower endthe lever 'l has pivotally secured thereto rods 31 and 38 which lead from the lever to the machine element to be controlled by the lever.

' Referring now more specifically to Fig. 4, there is here illustrated one of the valves shown associated with the upper end of the handle 1. Such valve comprises the body generally" indicated at 46, the body'being substantially tubular in form and provided at its lower end with a cylindrical recess, the open lower end of which is closed by a screw plug 55. The upper end of the body 4? likewise has a cylindrical opening in which is mounted 'a bearing ring 5| through which extends the knob |4 previously referred to. The knob I4 is generally cylindrical in form with the lower end thereof of reduced diameter and extending through an-annular valve member 59. The lower 'end of the knob M, where it passes through the annulus 59, is provided with a peripheral groove adapted to receive a retainer such as a snap ring. The stem M of the knob l4, where it passes through the annulus 59, has a peripheral groove M1) in which is positioned a pressure seal so that pressure may not pass the reduced section M where it passes through the valve annulus 50.

The upper end of the cylindrical cavity within the valve body 46 is finished off as at 54 to provide a valve seat with which a sealing ring indicated at 55 and carried by the annulus 50 may have contact.

The annulus 50 is urged upwardly and the sealing member is urged against the seat 54 by means of a spring 57 which is under compression by having engagement with the inner face of the plug 56. It will be observed that the strength of the spring 51 or, in other words, the initial loading placed on the spring 51, as the screw plug 55 is inserted, determines the amount of pressure or axial force necessary to be applied to the knob l4 for the purpose of unseating the valve which comprises the parts 54 and 55. p

Intermediately of its ends and adjacent a point of reduction in its outside diameter, the knob l4 carries a sealing ring 14a. In the adjacent end of and normally axially spaced from such sealing ring, the valve casing 46 is provided with an annular seat |4cZ with which the seal ring |4a is adapted to engage as the knob M is forced downwardly against the influence ofthe spring 51/ The casing of the valve is provided with a vent Me for the purposes hereinafter more fully ex- Dlained. r

.The mode of operation of the described apparatus is briefly as follows:

With a valve such as that illustrated in Fig.

' 4 mounted on each side of the upper end of the handle 1 so that the projection knobs l4 and l5- of such-valves are in engagement with the projections I9 and II respectively on the handle portion 9, the operator by gripping thehandle' portion 9 may move the handle manually unlessatendency to depress the knob M. ..In one form of construction, which has been used success-.1 fully in earth moving equipment, the strength of the spring 51 has been such that the end 9 of the handle is not permitted to rock until'the operator pushes against the handle with a force Whenever this predetermined load of 15 lbs. is applied to the handle portion 9 causing. the spring 51 in the valve to be compressed, the first movement of the knob I4 downwardly moves; sealing member 55 from the seat54. w en this occursair ,under pressure applied to the valve through the opening 41 from the gqoii'duit;v

was {twoavenues or smu -First, it ma pass through" the passages 81 the "connection. 4c. the conduit 23- and hence ta manure pressure motor. 2}. *The other-avenue of'fiow is 'tlirou'gh'the con-s s-tricte'd passage-around the valve seat l 4d and thence out of v the valve body through that-vent Me: If 3 the operator -thus pusheson the end: name with sufficient force tocause I an unseat iiigof the valvemember '55 by compressing the; spring" 51, a supplied amount or air under re du'ced 'pressurefisadrnitted" to the motor 2 4 and such motor gradually picksup-and offers" assist-- al'i ce-tothe operat'or-in-his' seekiiig td rotate: the-handle cloekwiseabout the axis itspivo'tar point at 35. Now as the operator continues-the application'of pressure iorwardlyon-th'e -pper end of the handle 9 indicating adesire-fora iu pure clockwise rotation "of the handle '1; this will" causethe knob HI- to descend a g'r'eater'di'stance; thus further restricting'the escape'passa'g'eioi the air past the seat Md building uppressure in the motor 24 and thus-increasing'theassistance which the booster motor 24 provides the operator hi's-efiortfto rotate the-handle I clockwise.=' Then if the operator still continues --forward pressure" on the handle s te a point where the sealing ring 7 Max is broughtflinto engagementwith" the seat Md thenthe'full pressure" Cif the air inthe-supply line w is-led to -the motor -24 and full assistance by such booster jack"-is-pro--' vided in rotating the handle I clockwise.

Shouldthe operator discontinue movement of handle portion 9, the pressure of the fluid yet acting on the piston- 28 01*29 will cause acontinued actuation of handle. 'i-about pivot until the depressed knob i l or [5 'can'shift to a position "closing communication between the fluid pressure supply line-and'the moto'r {M or 2 74. which had been assisting the operator in the actuation of'handle 1;

ii If now the operator releases the pressure ;on the. handle portion Q-the same sequence of events just described will 'occur, but in -reverse -order until finally; the'member -55"-i's seated orifthe seat" 54 whereupon the airin the motor -24 -is vented to the Iatmosphere through: the passages 48 and l 4e so that the operator will then again have the handle 7 entirely under his manual cofitrdi. i From the foregoing description of the invention it will be observed that the booster mechanism is effective not only for the purpose of providing assistance to the operator at the time when he needs help and when no longer the feel of the machine is important, but also, and of great importance, is the fact that the booster mechanism cuts in gradually and cuts out gradually so that at no time does the operator have a feeling that the control of the machine is either suddenly taken away from him or suddenly thrust back in his hands.

The modifications illustrated in Fig. 2 and Fig. 3 are substantially identical with that illustrated in Fig. 1. These modifications provide only one valve such as that illustrated in Fig. 4 and accordingly, the lower end of the handle I would be provided with only one booster motor so that the operator would in this instance move the handle in only one direction, 1. e. counterclockwise, as viewed in Fig. 2. In such construction the handle portion 9 may be prevented from rotating clockwise by the provision of a single abutment All replacing one ofthe valves for engagement with the projection l0.

' In Fig. 3 reference characters 4| through 44 havebeen 'appl iech :td the handle portion 8,:

denote respectively-the; grip, stem, body and. base-of suchl iandleportion. 'Wherrutilizing a form of construction with r only 'onei'val've, as illustrated in Figs. 2: and 3.

such construction is useful in those instances where there is need to apply a force one di-. rection only.

A's-previously indicated, the illustrated em-= J bodiment of the invention is primarily designedthe only change whichwould be required in the illustrated apparatus would be to supply a re turn conduit which would lead the oil from the passage" its; back to the supply tank at atmospheric pressure.-

the disclosed embodiment and the invention; reference has been made to the fact that. the strength of the springs?!" in the valves is such that they will yield when a force of about 15 lbs. is-applied by the operator against thehandle portion 9-. This value has been found in act'ual practice to be about the most satis factory for-most purposes. A force of 10 to-20 lbsxor-even 5 to" 30 lbs. can be used depending upon the desires of the operatorand the type of "equipment under control. -Generally, however,"a force of about 15 lbs. will be-found to be most satisfactory. Thelocation of the booster motors is not particularly critical. In the illustrated embodiment of the invention they have been placed below the level of the floor of the machine on which the operator stands in order that they may be out of the way of the operator. The only factor influencing their location is the distance away from the fulcrum po int"35 which will determine the size of the cross-sectional area of the piston thereof as compared with the unit pressure of the actuating fiuidand the amount of assistance which thebooster' motors are designed to supply.

{It j should be understood that the illustrated embodiments of my invention are but a few o'fthe various forms which such invention may haveand that various changes may bemade in theillustrated" embodiments without departing from the spirit of the invention. Thus, for example, it is within the contemplation of my invention to utilize electromagnets in place of the fiuid pressure motors 2| and 24, in which instance the knob I4 instead of controlling a fluid supply line would control an electrical circuit.

I claim:

1. In combination, a reciprocable member, a fixed support, a manually operable actuating handle having a main body part pivotally connected between its ends to said support and at one end to said member and a pivotal terminal part at the other end of said body part by which said handle is normally manipulated in opposite directions to correspondingly move said member, a pair of opposed single acting piston type fluid pressure motors each having one of its components mounted on said support and the other of its components connected to said body part at a point radially spaced from the pivotal connection of said body partto said support, and a pair of valves carried by said handle on opposite sides of the pivotal connection be tween said body and terminal parts and operatively connected with the respective motors to alternately admit fiuid under pressure thereinto and vent the same, each said valve comprising a valve body formed with an inlet port for fluid under pressure, an outlet port in communication with the associated motor, and a vent port, and a spring actuated valve member engaged with one of said body and terminal parts to yieldably resist pivotal movement o said terminal part with respect to said body part, each said valve member being arranged to close communication between such inlet and outlet ports and to vent the associated motor through such outlet and vent ports during manual manipulation of said actuating handle and being operative upon exertion of force thereon through said terminal part in excess of the yieldable resistance to open communication between such inlet and outlet ports while closing communication between such outlet and vent ports whereby the associated motor is operated to augment continued movement of said handle and of said reciprocable member.

2, In combination, a reciprocable member, a fixed support, a manually operable actuating handle having a main body part pivotally connected to said support and engaged with said member to reciprocate the latter responsive to oscillation of said main body part and a pivotal terminal part by which said handle is normally manipulated in opposite directions to correspondingly reciprocate said member, a pair of single acting piston type fluid pressure motors respectively arranged to actuate said body part in opposite directions and each having one of its components mounted on said support and the other of its components connected to said body part at a point radially spaced from the pivotal connection of said body part to said support, and a pair of valves carried by said handle on opposite sides of the pivotal connection between said body and terminal parts and operatively connected with the respective motors to alternately admit fluid under pressure thereinto and vent the same, each said valve comprising a valve body formed with an inlet port for fluid under pressure, an outlet port in communication with the associated motor, and a vent port, and a spring actuated valve member engaged with one of said body and terminal parts to yieldably a resist pivotal movement of said terminal part with respect to said body part, each said valve member being arranged to closecommunication between such inlet and outlet portsand to vent the associated motorthrough such outlet and vent ports during manual manipulation of said actuating handle and being operative upon exertion of force thereon through said terminal part in excess of the yieldable resistance to open communication between such inlet and outlet ports while closing communication between such v further apart than the seats in said valve bodies whereby, during movement of said valve members, a progressively decreasing portion of the fluid under pressure is vented to achieve a gradually increasing power boost eiiect on the manual actuation of said handle.

ROY H. ZEILMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,365,347 Schneider Jan. 11, 1921 1,385,658 Blasiar July 26, 1921 1,765,069 Gibson June 17, 1930 1,824,296 Rawson Sept. 22, 1931 1,928,915 Stout Oct. 3, 1933 2,138,148 Eckert -Nov. 29, 1938 2,360,542 Berry Oct. 17, 1944 2,380,705 Proctor July 31, 1945 FOREIGN PATENTS Number Country Date Great Britain Aug. 24, 1933 

